Electric selectors



Filed Sept. 28, 1956 Y im. a p

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Patented Mar. 6, 1962 3,024,402 ELEC'IRlC SELEC'I'GRS Alf F. Adel, Chicago, Ill., assignor to Raytheon Company, a corporation of Delaware Filed Sept. 28, 1956, Ser. No. 612,753 3 Claims. (Cl. S18-467) rfhis invention relates to channel or station selectors used in receivers, and in particular to electric channel selectors for energizing switch-type tuners.

The present invention is an improvement in electrical channel selectors and, while readily adaptable to television receivers, it is nevertheless not solely limited to this particular kind of receiver. Pursuant to the invention, the electric channel selector is adaptable to any type of receiver employing a switch-type tuner for electrically selecting any of the desirable and available frequencies within the area of reception of the receiver, while other fringe frequencies available only intermittently may be manually selected. These aspects of the invention are especially advantageous for employment of the selector in television receivers. In addition, the selector is an accurate device for positioning the tuning shaft of the associated tuner over the range of available channels and the device readily lends itself to the use of electrical tine tuning controls for final adjustment of the receiver for an optimum video display and associated audio signals. Simplicity of parts and relatively low cost are also features that distinguish the selector from those known to the prior art.

The novel features considered to be charactreistics of the invention are set forth with particularity in the appended claims. The invention itself, as well as additional objects and advantages thereof, will be more readily understood from the following description with reference to the accompanying drawing wherein:

FIG. l is a front elevational view of the selector with a front section of a support removed;

FIG. 2 is a top view of the selector;

FIG. 3 is a rear elevational view of the selector;

FIG. 4 is a schematic diagram of an electrical circuit for energizing the selector;

FIG. 5 is a detailed cross-sectional view of the rear surface of a support taken along the line A A in FIG. 1; and

FIG. 6 is a detailed cross-sectional view of the rear surface of a support taken along the line B-B in FIG. 1.

In accordance with the invention, there is provided a motor including a rotor and a field-producing winding. A gear is secured to the end of the rotor shaft. Upon energization of the winding, the rotor is rotatably energized and the rotor shaft is drawn into the electromagnetic field of said winding. A plurality of gears are rotatably secured in a support in a manner to be energized and, in turn, to transmit rotation of said rotor shaft gear to rotational movement of a selector plate. The selector plate is also rotatably secured to the support and has a plurality of cutouts around the circumference thereof and a plurality of stops mounted thereon and extending from the spaces between cutouts. In addition, said selector plate has means for holding and driving a tuning shaft of the tuner selected to be energized by the selector. One of said plurality of gears has a plurality of pins mounted thereon and extending therefrom, in a predetermined space relationship, which are positioned to make contact with and move along the peripheral surface of said cutouts when said one gear is energized. In this manner, said selector plate is driven by said pins. The quantity of stops in the selector plate is chosen to coincide with the number of channels to be received in the area of opera- Ition of the receiver. The spacing between stops is chosen by considering the number of degrees through which the selector plate must be rotated each time the selector is energized in order to have the associated tuner adjusted for the channels to be received. A plurality of levers, also rotatably mounted, are responsive to said pins and control the period of energization of said winding after initial energization of said winding. In essence, the levers cooperatively sustain energization of said winding and cause said selector plate to rotate. One of said levers, however, is responsive to contact with a rotating stop for terminating the cooperative action between Said levers, whereby said winding becomes deenergized and the selector plate is positioned.

Referring now to FIGS. l, 2 and 3 in which like parts of an embodiment of the invention have identical reference numbers, and to FIGS. 2 and 3 in particular, there is shown a motor l@ known to the prior art as a single-phase, shaded pole induction motor. A stator 11 of the motor is formed from a plurality of laminated iron sections, held together by rivets 12, 13, 14 and 15 (FIG. 3). A field producing winding 16 is wound around a portion of the stator and can be energized to generate an electromagnetic field by connecting lugs 17 and 18 to an alternating current supply. A circular opening 19 (FIG. 2) in said stator is dimensioned to accept the diameter of a squirrel cage rotor 2li therein. Flux-changing holes 21 and 22, and 23 through 26 into which shaded coils 27 and 28 are wound and secured in said stator, and depressions 29 and 30, provide the necessary rotation of the electromagnetic field developed by the winding 16 to energize the rotor 20 of the shaded-pole motor. The rotor shaft 3l is rotatably and slidably mounted in oil-filled bearings 32 and 33 which are riveted to brackets 34 and 35, which are, in turn, mounted on said stator. A spring 36, carried on said shaft, intermediate said rotor and the bearing 32, holds a gear 37 secured to the end of said shaft against the bearing 32. Screws 3S and 39, washers `4t) and 41, and nuts 42 and 43 secure the brackets 34 and 35 in place on said stator.

Screws 44 and 45 (FIG. 3) extending through said stator, with metal spacers 46 and 47 (FIG. 2) carried on said screws, and washers 44a and 45a secure the motor to a support 48 having threaded apertures to accept said screws. An opening y48a in the support in the vicinity of the gear 37, enables said gear to protrude therethrough when the rotor shaft is either depressed manually against the force exerted by the spring 36 or when the rotor is energized by the electromagnetic field and the rotor shaft is drawn into said field.

The support 48 is comprised of sections 49 and 50 riveted together in a manner to have a free area between said two sections. Referring now to FIGS. 1 and 2, a shaft 51 rotatably mounted intermediate said two sections of the support has secured thereon a gear 52, and, concentrically secured to the gear 52, a gear 53. A retention spring 54 is carried on said shaft 51, intermediate the gear 52 and the section 50, for holding said gears in position on said shaft. The gear 53 is positioned to make contact with the gear 37 when the rotor shaft is either manually or electrically energized as aforementioned. A shaft 55 (FIG. l), having secured thereon a gear 56, is also rotatably secured and positioned between said two sections in a manner to have the gear 52 drive the gear 56. Said gear 52 is driven concurrently with the gear 53 and drives the gear 56 one-half revolution for each revolution of the gear 53. Pins 57 and 58 (FIG. l) are mounted on and extend from the gear 56 toward the section 50. Said pins are spaced a predetermined distance and have predetermined dimensions for reasons to be given subsequently. A selector plate 59 is also rospaanse tatably secured to the section 49 of said support by means of a hollow shaft 66' and positioned to be driven by the pins 57 and 58 of the gear 56. The shaft 6i? has one end thereof staked to the selector plate 59, substantially at the center thereof, and another end machined to a suitable diameter for insertion into an opening in the section 49 and grooved to be heid in place by a spring washer or C ring 6l (FIG. 3). The inner diameter 62 of said shaft 6i! is preferably slightly larger than the tuning shaft (not shown) of associated apparatus to be energized by the rotation of the selector plate. Set screws 63 and 64, in threaded apertures on said shaft, are provided for securing the tuning shaft in place.

Referring to FlG. l in particular, the selector plate 59 has a plurality of spaced cutouts 65 extending around the circumference of said plate with a plurality of threaded stops 66, functioning as stops, secured in threaded apertures in the spaces adjacent the cutouts. The number of stops in said selector plate is determined by the number of channels to be received by electrically energizing the selector. However, the spacing between pins is determined by the characteristics of the tuner employed and by the necessity to correlate the frequencies to be received with the frequency response of the tuner as the tuning shaft is rotated. A more explicit description is given in a succeeding paragraph. Said pins 57 and SS are dimensioned and spaced to move along the peripheral surface of said cutouts over their rotational path, thereby driving said selector plate and the tuning shaft.

A pressure-actuated switch 67 is secured to a terminal strip 63, which, in turn, is secured to the section 49 by a staked stud 69 and a washer 7d on one side, and a threaded stud 71 in a threaded aperture and a washer '72 On the other side. As shown in FIG. 5, a lever 73 is rotatably secured to the inside surface of the section Si) by a staked stud 74, a circular spring washer 75 and a washer 76. Normally, a surface 77 of the lever is in contact with an actuator arm 7S of the switch 67 (FIG. 1) for closing said switch. The lever '73 is positioned to have the surface 77 contact the arrn 7 8 by a threaded stud 79, in a threaded aperture of the section 49, and a retention spring 80 carried thereon intermediate said section 49 and a surface 81 of said lever. Lugs 82 and 53 on the terminal strip 68 are provided for connecting the switch 67 to an alternating current supply, as will be ex plained subsequently. A surface 8d of the lever protrudes into the rotational path of said pins 57 and 58 to make contact with one of said pins over a portion of the rotational path of said pins. Contact between a pin and the surface 84 rotates the lever 73 clockwise, releasing the pressure on the arm 7S, whereby said switch is opened. However, a lever 85, also having a surface 86 in the rotational path of said pins, cooperates with said lever 73 to maintain said switch in the closed position until an arm S7 thereof contacts a rotating stop 66. As shown in FIG. 6, the lever 85 is rotatably secured to the inside surface of the section 50 by a staked stud S8, a circular spring washer 89 and a washer 90. A surface 91 of said lever 85 is positioned to rest on the arm 78, thus closing the switch 67 when said lever 85 is rotated clockwise by contact between said surface 86 and a pin 57 or 58. The arm 87 of the lever 85 is rotated into the path of said rotating stops 66 when said Contact occurs, but said lever is rotated counterclockwise when a stop contacts the arm 87. After being rotated counterclockwise, the surface 91 is removed from the arm 78 and, therefore, when a pin 57 or 5S contacts the surface 84 of the lever 73, opening the switch 67, the lever 85 cannot cooperate to maintain said switch closed.

It will be helpful at this point to note that, by having the threaded stops 66 in threaded apertures, said stops 66 need only be turned in so as not to make contact with the arm S7 in order to adjust the selector for the proper selection of channels.

An energizing` circuit for the selector is shown in FIG.

4. An alternating current source 92 is connected to a primary Winding 93 of a transformer 94. A step-down secondary winding 95 furnishes the proper operating voitage for energizing the winding f6 when a normally open on-oif switch 96, serially connected to said winding, is closed. The switch 96 is preferably of the type that opens a short time after it has been closed to enable the switch 67, shunt-connected across the switch 96, and the levers 73 and $5 to control the electromagnetic field generated by said winding Il6 thereafter. rhe switch 96 may conveniently be mounted on the cabinet of the television receiver.

ln summation, the operation of the selector is initiated by the closing of switch 96, which completes the circuit comprised of the secondary winding 95 and the winding f6, and causes an electromagnetic field to be generated in said winding. Rotation of said electromagnetic field by the configuration of the stator il?. and the coils 27 and 28 results in rotational excitation of said rotor and, in addition, rotation of the gears 52 and 53 by the gear 37 as the rotor shaft is pulled into said field. The pins 57 and 5S of the gear S6, in turn rotated by the gear 52, rotate the selector plate 59. The surface 77 of the lever '73 normally holds the switch 6/ closed, thus sustaining generation of said electromagnetic field. However, when the surface S4 of said lever contacts a pin 57 or Sii of the gear 56, said lever is rotated out of position, whereby the switch 67 is opened unless the lever cooperates with the lever 78 to maintain the switch 67 closed. 'fhe rotational distance said selector plate moves each time said switch 96 is closed is determined by the number and spacing between the stops 66 positioned in the selector plate that can contact the arm 37 of the lever 85. The arm A87 is rotated into the path of said stops simultaneously with the positioning of the surface 91 to hold the switch 67 closed by contact between the surface and a pin 57 or 5S. Until said arm contacts a rotating stop, said levers 73 and 35 hold the switch 67 closed. However, after said arm contacts a stop, and the lever is rotated out of position, said lever cannot hold the switch 67 closed when a pin 57 or 58 rotates the lever 73 counterclockwise, causing said motor to become inoperative. Thus, the tuning shaft secured in and rotatably energized by said selector plate is moved to a new position each time the switch 96 is closed.

Having described the operation of the selector, the requirements of the associated switch-tuner have inadvertently been described. As shown in FIG. l, the embodiment of the invention contains twelve stops and a similar number of cutouts. If all twelve stops are employed, the selector plate will require twelve periods of energization to complete a cycle. Similarly, if only a quarter of that number are used, only three periods are required. Thus, energization of the tuning shaft by the selector plate must correspondingly tune the tuner to the proper frequency when the motor becomes deenergized. It follows then, that, if various stops are turned in so as not to contact the arm 87, the selector plate and the tuning shaft will continue to rotate until a stop contacts the arm 87 and, subsequently, a pin 57 or 53 rotates the lever 73 out of position.

ln its adaptation to a television receiver, the selector can also readily be incorporated into a remote control system for tuning or monitoring available channels. lt is obvious that the switch 96 can either be mounted on the cabinet of the receiver or said switch can be moved out to a remote location, from whence the selector can be energized. It also follows that another switch 97 may be connected in shunt with the switch 96 on the cabinet for energizing the selector either at the cabinet or remotely. The operation of the selector by means of the switch 97 in conjunction with the ordinary fine tuning, volume and remote speaker controls found in the common remote control system results in a very desirable system.

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While the foregoing description has referred to use of the selector in conjunction with switch-type tuners of television receivers, it will be understood that the invention is not intended to be limited to this medium of receiving U.H.F. or V.H.F. frequencies. Furthermore, while a shaded-pole induction motor having a squirrel cage rotor has been described in the embodiment of the invention, it will be understood that the energization of the rotor is not limited to this particular type of motor.

What is claimed is:

1. In combination, a rotatably mounted plate having a plurality of stops mounted about the periphery thereof separated by cutouts, a rotatably mounted device for driving said plate having a plurality of pins mounted on the surface thereof and extending therefrom arranged to engage said cutouts in said plate, motor means including a rotatable and slidable member adapted to rotate said plate-driving means, a source of energy for said motor means, means connected intermediate said motor means and `said energy source for initially energizing said motor means, means including a switch having a set of normally open contacts for maintaining said motor means energized until said plate rotates a predetermined number of degrees, rotatably mounted means including a first lever in contact with said switch for actuating said switch under control of said pins and one of said rotating stops for disabling said switch and a second lever under control of another rotating pin cooperating with said first lever to maintain said switch actuated and adapted to be rotated out of contact with said motion switch by one of said rotating Stops disabling said switch permitting said contacts to open, whereby said plate is positioned.

2. In combination, a rotatably mounted plate having a plurality of stops mounted about t-he periphery thereof separated by cutouts, a rotatably mounted device for driving said plate having a plurality of pins mounted on the surface thereof and extending therefrom arranged to yengage said cutouts in said plate, motor means including a rotatable and slidable member adapted to rotate said plate-driving means, a source of energy for said motor means, means connected intermediate said motor means and said energy source for initially energizing said motor means including a switch having a set of normally open contacts, means for maintaining said motor means energized until said plate rotates a predetermined number of degrees, rotatably mounted means including a first lever having a first surface in contact with said switch for closing said contacts and a second surface under control of a rotating pin over a portion of the rotating path of said pins for moving said first lever for deactuating said `switch and a second lever having a rst surface under control of another rotating pin cooperating with said first lever over another portion of the rotating path of said pins, a second surface to maintain in cooperation with ,said rst lever said switch actuated and adapted to rotate said second lever out of contact with said switch when contacted by one of said rotating stops permitting said contacts to open; whereby said plate is positioned.

3. `In combination, a rotatably mounted plate having a plurality of stops mounted above the periphery thereof separated by cutouts, a rotatably mounted device for driving said plate having a plurality of pins mounted on the surface thereof and extending therefrom arranged to engage said cutouts in said plate, a second device in contact with said `first driving device 'for rotating said first driving device, electric motor means including `a stator, a rotor mounted on a slidably mounted shaft, and a fieldproducing winding wound on said stator, a device attached to said shaft adapted to rotate said second device, a source of energy, a switch connected intermediate said winding and said source of energy yfor initially energizing said windings whereby said rotor and said plate are rotated, means including a second switch having a set of normally open contacts shunting said switch for maintaining said motor rotating until said plate rotates a predetermined number of degrees, rotatably mounted means including a `first lever having a first surface in contact with said contact for activating said contacts and a second surface under control of a rotating pin over a portion of the rotating path of said pins for moving said first lever bringing its first `surface out of contact with said contacts and a second lever having a first surface under control of another rotating pin cooperating with said first lever over another rotating portion of the rotating path of said pins, a second surface to maintain in cooperation with said first lever said contacts activated and a third surface adapted to contact one of said rotating stops rotating said second surface of said second lever out of contact with said contacts permitting them to open; whereby said plate is positioned.

References Cited in the file of this patent UNITED STATES PATENTS 719,198 Cyr Jan. 27, 1903 1,119,967 Landsiedel Dec. 8, 1914 2,174,275 Raney Sept. 26, 1939 

